1. Field of the Invention
This invention relates to a novel copolymer, a method for the manufacture thereof and uses thereof. More particularly, the invention relates to a copolymer containing in the molecular unit thereof a carboxyl group and/or a salt thereof and further containing therein, as a side chain and in the shape of a comb, an adduct of an alkylene oxide, to a method for the manufacture thereof, and to uses thereof.
2. Description of Prior Arts
Heretofore, polysulfonic acids and salts thereof such as lignosulfonic acid and salts thereof, naphthalenesulfonic acidformaldehyde condensates and salts thereof (German Pat. No. 1,238,831) and sulfonated melamine resins and salts thereof, oxycarboxylic acids and salts thereof such as gluconic acid and salts thereof and glucoheptonic acid and salts thereof, and mixtures thereof (U.S. Pat. No. 3,686,133) have been used for the purpose of improving the fluidity (water-reducing effect) of mortars and concretes in mortar and concrete works, improving the strength and durability of set mortar and concrete products, and minimizing the possibility of such set products sustaining cracks on aging. Naphthalenesulfonic acidformaldehyde condensates and salts thereof and sulfonated melamine resins and salts thereof, however, fail to manifest the expected water-reducing effect when they are added in amounts falling in the lower-limit zones of the respective specified ranges. The oxycarboxylic acids and salts thereof retard and impair the setting of mortars and concretes when they are added in substantial amounts with a view to enhancing the fluidity of mortars and concretes but fail to bring about ample water-reducing effect on mortars and concretes.
It is, therefore, an object of this invention to provide a novel copolymer, a method for the manufacture thereof, and uses thereof.
Another object of this invention is to provide a copolymer useful as a cement dispersing agent capable of manifesting an outstanding water-reducing effect, a method for the manufacture thereof, and uses thereof.